Separable electrical circuit assembly



June 13, 1967 R. TRAVIS 3,325,769

SEPARABLE ELECTRICAL CIRCUIT ASSEMBLY Filed Sept. 25, 1964 |o=:i+ I2 l II I II I I lZg g g :4

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I FIG] FIG.6- Ll 30 INVENTOR 44 Lawrence R. Travis United States Patent3,325,769 SEPARABLE ELECTRICAL CIRCUIT ASSEMBLY Lawrence R. Travis,Pitcairn, Pa.', assignor, by mesne assignments, to Rogers Corporation, acorporation of Massachusetts Filed Sept. 25, 1964, Ser. No. 399,217Claims. (Cl. 339-176) The present invention relates to electricalcircuit assemblies for the termination and connection of electricalconductors, and more particularly to electrical circuit assemblies foruse with flat flexible electrical connection conductors.

Flat flexible cables in which a number of usually flat conductorsare'disposed and bonded between suitable plastic insulating materialsmay be used to advantage in a great number of applications. One of theproblems of utilizing such flat flexible cables is that of providingsuitable connection or termination of the cable to other electricalcircuitry. A simple, economical, and reliable electrical terminationsystem has been disclosed in copending application Ser. No. 352,156,filed Mar. 16, 1964, and assigned to the same assignee as the presentapplication, which adequately solves the termination problems usuallyassociated with flexible cables.

The most common situation for termination of a flat flexible cable is tohave a unitary connector at the end thereof which fits into a matingreceptacle. In certain situations it would be highly advantageous tohave the capability of providing a multiple connector assembly in whichvarious of the individual conductors with the associated contacts areavailable for connection at different receptacle areas. Thus, by such anassembly, conductors, one or more, would have their separate connectorsavailable for connection at a given receptacle area, while otherconductors, with their associated connectors, could be provided at otherconnecting areas.

It is therefore an object of the present invention to provide a new andimproved connector assembly utilizing a readily adaptable connector orterminating device.

It is a further object of the present invention to provide a new andimproved connector assembly utilizing a connecting or terminating devicewhich may be readily separated for different circuit applications.

It is a further object of the present invention to provide a new andimproved connector assembly for use with flat flexible cable in which aconnecting or terminating device is utilized which is readily separableto provide separate connectors for the various conductors of the cable.

Broadly, the above cited objects are accomplished by providingelectrical connector assembly for use with flexible cable by providing aformed termination or connector member which is frangible to permit theready separation of one or more of the conductors.

These and other objects and advantages of the present invention willbecome more apparent when considered in view of the followingspecification and drawings in which:

FIGURE 1 is a plan view of flat flexible cable as utilized herein;

FIGURE 2 is a front elevation view of FIGURE 1;

FIGURE 3 is a plan view of the mandrel as used herein;

FIGURE 4 is a front elevation view of FIGURE 3;

FIGURE 5 is a side elevation view of FIGURE 3;

FIGURE 6 is a plan view of the connector member as utilized herein;

FIGURE 7 is a side elevation view of FIGURE 6;

FIGURE 8 is an enlarged view of one of the broken away contact connectormembers of FIGURE 7;

3,325,769 Patented June 13, 1967 FIGURE 9 is a three-dimensional view ofthe connector assembly as provided herein showing various conductormembers separated to provide individual contact members, and

FIGURE 10 is a three-dimensional view of another form of the presentinvention;

Referring to FIGURES 1 and 2, a section of flat flexible cable is shownhaving a plurality of elongated electrical conductors 10 sandwichedbetween two electrically insulating layers 12 and 14. The conductors 10,for example, may have a rectangular cross section as shown and comprisecopper. One or both of the insulating layers 12 and 14 may, forinstance, comprise a film of an aromatic polyirnide or aromaticpolyimide-imide resin. To secure and bond the conductors 10 between thelayers 12 and 14, a flexible epoxy adhesive may be used. For furtherdetails as to the process and materials used in the fabrication of theflexible cable reference is made to the above copending application.

Between the conductors 10 are insulating portions 16, which are parallelto the conductors 10 and thus separate the conductors 10 so as toprovide separate electrical circuits through each of the conductors.Slits 18 may be cut back a predetermined distance into the insulatingchannel 16 from the end 20 of the flexible cable. The slits 18 permitthe separating of the various individual conductors 10 at the end 20 aswill be described below.

In FIGURES 3, 4 and 5, a mandrel 22 is shown about which one end of theflexible cable is wrapped. The flexible cable is secured about themandrel with, for example, a suitable epoxy resin. The mandrel 22includes a plurality of flat portions 24 which correspond to therespective conductors 10 of the flexible cable and over which theconductors 10 are placed. Between the flat portions 24 are web portions26 which have a thin cross sectional area. The mandrel 22 may comprise aplastic insulating material. The web portions 26 are designed to have athin cross section so as to be frangible so that the various flatportions 24 may be separated by the breaking of the web portion 26. Theweb portions 26 need only be thick enough to permit the flowing of theplastic material during its molding process. With the conductors 10 ofthe flexible cable fitting over the flat portions 24 of the mandrel 22and the insulating channels 18 fitting over the frangible web portions26 and the cable secured to the mandrel, the cable is ready for moldinginto a connector or termination member 28 which is shown in FIGURES 6and 7.

Referring to these figures, a formed connector or termination member 28is shown which may comprise a plastic insulating material and which ismolded directly over the mandrel 22 after the cable has been secured tothe mandrel. The connector member 28 comprises a plurality of contactreceiving portions 30 which are connected by a plurality of frangibletab portions 32. The termination member 28 also has an optimal raisedback portion 34, better seen in FIG. 7, which serves as a means forgripping the connector member 28 for inserting or with drawing it fromanother connector or for mounting of an interfacial seal. In each of thecontact receiving portions of the termination member 28, a contactopening 36 is provided. The contact receiving portions and openings 36therein are so aligned to be in position over the respective conductors10 of the cable.

After the formed termination member has been molded directly over themandrel 22 with the cable secured thereto, the insulation appearing onthe outside of the insulating film layer 12 is removed by a chemicalprocess. The areas exposed by the contact openings 36 establish contactareas. These contact areas are then electroplated, for example withgold, to provide a good electrical contact structure 38 as is well knownin the art. The chemical removal and electroplating processes arediscussed in the above copending application. FIGURE 8 shows the contactstructure 38 appearing through an opening 36 with the molded connectormember 28 fitting therearound to provide a one piece connector andcontact assembly. A locking lug 40 is molded into the termination member28 so that a locking structure may be fitted over the lug 40 when asecure connector is desired or for the utilization of an adapterconnector. I

The frangible tab portions 32 of the formed connector member 28 aredisposed over the Web portions 26 of the mandrel 22. The tab portions 32are so molded as to have 'a cross section thin enough only to permit theplastic insulating material to flow therethrough during the moldingprocess. Using such a thin web tab portion thus permits the readybreaking through of the insulating material thereof to easily separatethe various contact receiving portions 30 of the termination member 28.

In order to provide a single conductor and connector member, as shown inFIGURE 8, it is only necessary to break through the tab portions 32 ofthe connector member 28 and through the frangible web portions 26 of themandrel 22. This could be easily done since, as described above, the weband tab portions are designed to be relatively thin to permit suchseparation. The slits 18, see FIGURE 1, would then serve to permit suchseparation of one of the conductors with its associated connector member28 to any desired length. Each separated connector would have its owncontact portion 38 which would appear through the contact opening 36 topermit connection to various electrical fixtures.

FIGURE 9 shows a flexible cable assembly in which three connectormembers 42, 44 and 46 are shown broken from an original unitarystructure. The three connectors 42, 44 and 46 are broken from a unitaryconnector member to provide, respectively, a one contact, a two contact,and a three contact connector structure. The flexible cable is shownslit back away from the connectors 42, 44 and 46 so that theseconnectors may be inserted into various female receptacles. A unitaryconnector member 50, which maybe an unbroken member fabricated asdescribed herein, is shown connected to the other end of the flexiblecable.

In FIG. 10 is shown another form of the connector assembly as taughtherein. The connector assembly as shown takes the form of a femaleassembly with a contact structure 58 appearing within a contactreceiving structure 60 which as aperture 62 therein for receiving a maleconnector. A frangible web member 64 connects adjoining contactreceiving members and permits the ready separation of the variouscontacts as described above.

It can, thus, be seen by such an assembly that a readily adaptableflexible cable connector assembly is provided which may be used in agreat variety of situations and may easily be changed to accommodate agreat number of circuit applications. Also it should be noted that thevarious individual contact elements could be cut or sawed apart afterthe assembly has been fabricated, if made necessary by the use ofthicker areas between the conductors.

Although the present invention has been described with a certain degreeof particularity, it should be understood that the present disclosurehas been made only by way of example and that numerous changes in thedetails of constructure, fabrication and the combination and arrangementof parts, elements and materials may be resorted to without departingfrom the scope and spirit of the present invention.

I claim:'

therein comprising, a mandrel about which a portion of 'said cable isdisposed, said mandrel including a plurality of frangible web portions,a termination member to encapsulate said mandrel, said terminationmember including'a plurality of frangible tab portions, each of said tabsaid mandrel so that said mandrel and said termination member may beeasily broken apart.

2. An electrical connector assembly for use with flat flexible cablehaving a plurality of conductors disposed therein comprising, a mandrelabout which an end portion of said cable is disposed, said mandrelincluding a plurality of frangible web portions disposed between saidflat portions, a molded termination member to encapsulate said mandrel,said molded member including a plurality of contact receiving portionsdisposed over the corresponding conductors of said cable, and afrangible tab portion connecting said contact receiving portions, eachof said tab portions corresponding with one of said web portions of saidmandrel so that said mandrel and said molded member may be easily brokenapart at the web and tab portions respectively to provide a number ofseparate contact terminations.

3. An electrical connector assembly for use with flat flexible cablehaving a plurality of conductors disposed therein comprising, a mandrelabout which an end portion of said cable is disposed, said mandrelincluding a pluraltiy of substantially flat portions over which theconductors of said cable are disposed and a plurality of frangible webportions disposed between said flat portions, a molded terminationmember to encapsulate said mandrel, said molded member including aplurality of contact receiving portions disposed over the correspondingconductors of said cable, said contact receiving portions having acontact opening therein through which a portion of the correspondingconductor appears for contact purposes, and a plurality of frangible tabportions connecting said contact receiving portions, each of said tabportions corresponding with one of said web portions of said mandrel sothat said mandrel and said molded member may be easily broken apart atthe web and tab portions respectively to provide a number of separatecontact terminations. 7

4. An electrical connector assembly for use with flat flexible cablehaving a plurality of conductors dis-posed therein comprising, a mandrelabout which portion of said cable is secured, said mandrel including aplurality of substantially flat portions over which the conductors ofsaid cable are disposed and a plurality of web portions disposed betweensaid flat portions, said web portions being relatively thin compared tosaid flat portions, a formed termination member molded over saidmandrel, said formed member including a plurality of contact receivingportions disposed over the corresponding conductors of said cable, saidcontact receiving portions having a contact opening therein throughwhich a portion of the corresponding conductor appears for contactpurposes, and a plurality of tab portions connecting said contactreceiving portions, said tab portions being relatively thin compared tosaid contact receiving portions, each of said tab portions correspondingwith one of said web portions of said mandrel so that said mandrel andsaid formed member may be easily broken apart at the web and tabportions respectively.

5. An electrical connector assembly for use with flat flexible cablehaving a plurality of conductors disposed therein comprising, amulti-section mandrel comprising an insulating material about which aportion of said cable is secured, said mandrel including a plurality ofsubstantially flat portions over which the conductors of said cable aredisposed and a plurality of frangible web portions disposed between saidflat portions, a multi-section formed termination member comprising aninsulating material molded about said mandrel to encapsulate saidmandrel, said formed member including a plurality of contact receivingportions disposed over the corresponding conductors of said cable, saidcontact receiving portions having a contact opening therein throughwhich a portion 5 6 of the corresponding conductor appears for contactpur- References Cited poses, and a plurality of frangible tab portionsconnect- UNITED STATES PATENTS ing said contact receiving portions, eachof said tab por- 2,396,725 3/1946 Thomas 339 176 X tions correspondingwith one of said Web portions of said 3 9 2 393 3 1 3 Valach 339 176mandrel so that said mandrel and said formed member 5 3,149 397 9/1964 Mi k 339 176 may be easily-broken apart at the web and tab portionsrespectively to provide a number of separate contact ter- MARVINCHAMPION Primary Examinerminations. W. DONALD MILLER, Examiner.

1. AN ELECTRICAL CONNECTOR ASSEMBLY FOR USE WITH FLAT FLEXIBLE CABLEHAVING A PLURALITY OF CONDUCTORS DISPOSED THEREIN COMPRISING, A MANDRELABOUT WHICH A PORTION OF SAID CABLE IS DISPOSED, SAID MANDREL INCLUDINGA PLURALITY OF FRANGIBLE WEB PORTIONS, A TERMINATION MEMBER TOENCAPSULATE SAID MANDREL, SAID TERMINATION MEMBER INCLUDING A PLURALITYOF FRANGIBLE TAB PORTIONS, EACH OF SAID TAB PORTIONS CORRESPONDING WITHONE OF SAID WEB PORTIONS OF SAID MANDREL SO THAT SAID MANDREL AND SAIDTERMINATION MEMBER MAY BE EASILY BROKEN APART.